Note

If you are a Prophesee customer, you can access datasheets and user manuals in our Knowledge Center after requesting an account. This page provides additional details on the sensor’s Region of Interest features, focusing on how to configure them with the SDK.

Region of Interest

Each pixel contains a latch to activate/deactivate pixels in the pixel array. When deactivated, the pixel does not perform any detection which limits the number of events passing through the readout and the dynamic current consumption to active pixels only.

The Region of Interest (ROI) is a pixel area used to set the only active area of the sensor. We also define the Region of Non-Interest (RONI) as a pixel area that can be set as the inactive area of the sensor.

Selection of the mode is done using the function Metavision::I_ROI::set_mode() of the facility I_ROI. For the Python API, check Python HAL bindings page.

The ROI facility can be used in Studio and is demonstrated in some samples like metavision_hal_showcase. The picture below shows an example of ROI generated with Metavision::I_ROI::set_window() mode:

Region of Interest and Region of Non-Interest

Note

Some ROI functionalities are not yet available in the SDK API or in Studio. For example the ROI mode Metavision::I_ROI::set_lines() which can be used for subsampling the pixel array is not yet available in Studio. Nevertheless, you can use this feature with the SDK API as demonstrated in metavision_viewer sample. For more details on this feature, please refer to your sensor datasheet.

The table below provides a brief summary of ROI features depending on the sensor version:

Feature

Description

Gen31

Gen41/IMX636

GenX320

Row/Column specification mode

(Metavision::I_ROI::set_lines())

Selection of Lines and Columns

to activate allowing to draw

rectangular areas to activate

(multiple zones BUT “symmetric”

areas also activated)

Available

(ROI or RONI)

Not Available

natively

(can be achieved

with Pixel mask)

Single Windows

specification mode

(Metavision::I_ROI::set_window())

Selection of a single rectangular

area to activate by its

coordinates

Not Available

natively

(can be achieved with

Row/Column mode)

Available

(ROI or RONI)

Available

(ROI or RONI)

Pixel mask specification mode

(I_RoiPixelMask)

Low level ROI interface to

configure a “bitmask” ROI

Not Available

Available

Multiple Windows

specification mode

(Metavision::I_ROI::set_windows())

Selection of Rectangular Areas

to activate by its coordinates

(18 zones max, symmetric areas

not activated)

Not Available

Available

(ROI or RONI)

The SDK allows to store part of the ROI configuration in a JSON file as described in the Saving/loading the camera settings section of the Camera Settings programming guide. The following example illustrates a typical section for configuring the ROI for a single window:

{
 "roi_state": {
  "window": [
   {
    "x": 35,
    "y": 42,
    "width": 256,
    "height": 228
   }
  ],
  "columns": [],
  "rows": [],
  "enabled": true,
  "mode": "ROI"
 }
}